Reexpandable Sealing Tape

ABSTRACT

The elastically reexpandable sealing tape for sealing a joint comprises an elastically expanding foam strip ( 1 ) of rectangular cross section, which is held in a compressed state. This is done by means of at least one releasable seam, which extends across the sealing tape and consists of at least one thread ( 7 ), which passes through the foam strip ( 1 ).

The present invention pertains to an elastically reexpandable sealingtape for sealing a joint, such as that between a frame profile of, forexample, a window or a door, and the wall of a building, according tothe preamble of claim 1.

A sealing tape of this type is known from, for example, EP 1131 525 B1.The known sealing tape consists of an elastically expanding foam stripof rectangular cross section, which, in the compressed state, iscompletely surrounded by a wrapping, which consists of a plastic foil,which also forms a tear-open tab extending in the longitudinal directionof the sealing tape, for which purpose the plastic foil is bonded toitself to form a predetermined tear site. To hold the foam strip inplace inside the pocket formed in this way, the strip is bonded to thewrapping, and the wrapping in turn can be attached to a frame profile bymeans of separate adhesive means, such as double-sided adhesive tape.

Sealing tapes of this type are attached to the frame profile to bescaled, and after the frame profile has been installed in the roughopening in the wall of the building, the wrapping is torn open to allowthe foam strip to recover elastically and thus to seal off the frameprofile against the wall.

In the case of the known sealing tapes, however, after the wrapping hasbeen torn open, a portion of the wrapping material necessarily remainson the structure, especially on the part located between the frameprofile and the foam strip. This is often undesirable. In addition, itis very complicated to fabricate the sealing tape because of thenecessary step of applying the wrapping.

A sealing strip for attachment to a window frame is known from EP 0 530653 B1. This strip consists of a rigid channel with a U-shaped crosssection and an elastically compressed foam strip arranged therein. Thechannel is closed off by a dimensionally stable cover strip, which isheld in detachable, positively-engaging connection with the front regionof the channel walls. The cover strip is connected in a banner-likemanner to a limp strip element, which is guided over one edge of thecover strip and into the channel of the sealing strip. By pulling on thelimp strip element, the cover strip can be detached from the channel, sothat the compressed foam strip can expand. This design is extremelycomplicated.

A sealing strip which consists of a surface strip for attachment to aframe profile with a foam strip arranged on top of the surface strip isdescribed in U.S. Pat. No. 4,204,373. The foam strip is covered by afoil of paper or plastic, which is adhered to the surface strip andholds the foam strip in the compressed state. Rip cords, which can beused to tear open the sheet after the frame profile equipped with thesealing strip has been installed in the building structure, extend alongthe edge of the cover sheet.

It is an object of the present invention to provide a sealing tape ofexpanding foam which can be held in a compressed state in adimensionally stable manner and released easily for expansion.

This object is solved by a sealing tape comprising the features of claim1.

The elastically expanding sealing tape according to the inventioncomprises an elastically expanding foam strip of rectangular crosssection, which is held in the compressed state. This is accomplished bymeans of at least one breakable seam consisting of at least one threadextending across the sealing tape.

In the present invention, therefore, the at least one seam holds thefoam strip in the compressed state even after the strip has been unwoundfrom the roll. Breaking the seam allows the foam strip to expand.

In a preferred embodiment with double-sided adhesive tape on the bottomsurface and a foil-type covering on the top surface of the foam strip,the seam is also sewn through the foil-type covering. The sealing tapeis first adhered to the frame profile element, and then the covering ispulled off the sealing tape, as a result of which all of the seams arebroken, and the foam strip is free to expand.

So that the covering can be removed more easily, a tear-open tab can beattached to the covering.

Advantageous embodiments of the invention are subject of the dependentclaims.

The invention is explained in greater detail below on the basis of theembodiments illustrated in the drawings:

FIG. 1 is a cross-sectional view of a first embodiment of theelastically expanding sealing tape according to the invention;

FIG. 2 is a cross-sectional view of a second embodiment of theelastically expanding sealing tape according to the invention;

FIG. 3 is a cross-sectional view of a third embodiment of theelastically expanding sealing tape according to the invention;

FIG. 4 is a cross-sectional view of a fourth embodiment of theelastically expanding sealing tape according to the invention;

FIG. 5 is a cross-sectional view of a fifth embodiment of theelastically expanding sealing tape according to the invention; and

FIG. 6 is a cross-sectional view of a sixth embodiment of theelastically expanding sealing tape according to the invention.

In the drawings, the wrappings, adhesive tapes, and silicone papers areshown a certain distance away from the foam body, so that it is easierto distinguish from each other the individual elements which form thesealing tape. In reality, these elements lie directly on top of eachother or on the compressed foam strip.

FIG. 1 shows an elastically expanding foam strip 1, which, in thepresent example, has a rectangular cross section. The foam strip 1 canbe completely impregnated to delay its reexpansion after thecompression. Any suitable material can be used for the foam strip 1;either open-cell or closed-cell soft foams will be used depending on thearea of application. Preferred materials are polyurethane foam andpolyethylene foam. It is also possible to use a multilayer foam strip 1with various layers laminated onto each other.

A piece of double-sided adhesive tape 6, which serves to attach thesealing tape to a structural element to be installed, such as a frameprofile of a window or door, can be attached directly to the bottomsurface of the foam strip 1. The downward facing, outside surface of theadhesive tape 6 is preferably kept covered by a piece of silicone paper10 or the like, shown in broken line, until the sealing tape is attachedto the structural element.

It should be emphasized at this point that, in practice, the adhesivetape 6 is very often realized by a layer of adhesive, which has beenapplied to a piece of silicone paper 10 or the like, which is thenaffixed in this form to a web of foam material. In some cases, a scrimor a support film, nonwoven fabric, or the like can also be embedded inthis adhesive layer to increase the tensile strength. The expression“adhesive tape” used above should therefore also comprise adhesivelayers of the type described here.

In the embodiment shown in FIG. 1, the foam strip 1 is held in thecompressed state by four seams consisting of threads 7, which extend inthe longitudinal direction of the foam strip 1, these threads passing inthe known manner through the strip from top to bottom. The seam thusalso guarantees that the foam strip 1 has a cross-sectional shape in thecompressed state which is as close to rectangular as possible.

The seams consisting of the threads 7 are released preferably after thesealing tape has been attached to the structural element to be sealed.In the embodiment of FIG. 1, seams are preferred in which the threadscan be very easily removed simply by pulling on one end of the thread,so that the material of the foam strip 1 can expand elastically to itsoriginal shape at the construction site. In general, single-thread andtwo-thread seams can be used.

The embodiment of FIG. 2 differs from that of FIG. 1 in that a covering2 is provided on the top surface of the foam strip 1. The material ofthe covering 2 can be sheeting, a scrim, paper, or some other material,which preferably is resistant to bending in the transverse direction ofthe scaling tape and is limp in the longitudinal direction of thesealing tape. It is also possible to use a plastic film laminated to asubstrate (e.g., nonwoven material), or a fabric-reinforced sheet. Allthese materials are described by the expression “foil-type”.Combinations of these materials are also possible, especially in theembodiment of FIG. 5 described below.

The thread 7 here and in all of the subsequent embodiments is sewnthrough the covering 2. As a result, the foam strip 1 is held relativelyhomogeneously in the compressed state, and the degree to which the foamstrip 1 bulges between the stitches is reduced.

In FIG. 2, a tear-open tab 3, which is preferably formed out of one ofthe materials of the covering 2 mentioned above, is bonded firmly to thecovering 2 so that it lies flat. Here the tab is attached to the entiretop surface of the sealing tape, but it is also possible to establish abond only in some desired partial area. The bonding is usuallyaccomplished by the use of an adhesive.

Here, too, single-thread seams or two-thread seams can be used, but atwo-thread seam offers the advantage that the two threads can be ofdifferent thicknesses. The thread 7 of the seam which passestransversely through the foam material 1 is usually dimensioned in sucha way that it can be easily broken. The thread of the seam which linksthe loops of the thread 7 together on the outside surface of thecovering 2 is dimensioned in such a way that it does not break when thecovering is torn from the sealing tape. This makes it especially easy toremove the threads 7 from the foam strip 1.

The embodiment according to FIG. 3 differs from that of FIG. 2 in thatthe tear-open tab 3 is folded over at one end and thus has the shape ofa “J”. This folded-over end is attached to the terminal area of thecovering 2 which is opposite the free end of the tear-open tab 3. As aresult, the covering 2 can be very easily peeled off the foam strip 1 bypulling on the tear-open tab 3. When the covering 2 is being peeled off,the threads 7 automatically are separated or are broken and thus releasethe foam strip 1 for reexpansion.

FIG. 4 shows another embodiment, which differs from that of FIG. 3 tothe extent that the threads 7 are also sewn through the adhesive tape 6.As a result, another stabilizing effect is obtained, especially when theadhesive tape 6 is stiff in the transverse direction.

FIG. 5 shows another embodiment of the invention. Here the covering 2 isdesigned as a two-part wrapping with separate sections 2 a and 2 b,which almost completely surround the foam strip 1.

In the example shown here, the first section 2 a completely covers alateral surface and the top surface of the foam strip 1 and half of thesecond lateral surface. In addition, a first edge strip 18 of thesection 2 a is folded over onto an edge area of the bottom surface ofthe foam strip 1. On the opposite side, a first extension strip 3 a ofthe first section 2 a of the covering 2 projects from the foam strip 1and forms part of the tear-open tab 3.

The second section 2 b of the covering 2 covers only the lower half ofthe second lateral surface of the foam strip 1, and its second edgestrip 16 covers the second edge of the bottom surface of the foam strip1. The second section 2 b also forms a second extension strip 3 bparallel to the previously mentioned first extension strip 3 a andcooperates with it to form the tear-open tab 3. The first and secondsections 2 a and 2 b of the covering 2 are held together near the foamstrip 1 by a seam, which is symbolized in FIG. 5 by the number 15, andwhich can be a welded seam, an adhesively bonded seam, or a sewn seam.

The edge areas of the adhesive tape 6 cover the edge strips 16, 18 ofthe covering 2 located on the bottom surface of the foam strip 1 andhold these firmly in place. The adhesive bond is strong enough to resista certain recovery force produced by the foam strip 1 in the compressedstate but at the same time is weak enough to yield to a tearing forcewhen, after the sealing tape has been attached to a structural element,the tear-open tab 3 is pulled.

The covering 2 and the seams consisting of the threads 7 thus worktogether to hold the foam strip 1 in the compressed state.

When, after this sealing tape has been attached by means of the adhesivetape 6 to the structural element, the tear-open tab 3 is pulled, theedge strip 16 comes away from its adhesive bond first. Continuing topull on the tear-open tab 3 has the effect of releasing the threads 7,and finally the other edge strip 18 comes away from its adhesive bond,so that the covering 2 is completely separated from the sealing tape,and the foam strip 1 can recover completely, that is, expand.

The tear-open tab 3 formed by the two extension strips 3 a and 3 b canalso be arranged on the upper edge or lower edge of the second lateralsurface of the foam strip 1.

FIG. 6 shows another embodiment of the inventive sealing tape. Itdiffers from that according to FIG. 5 in that, first, the covering 2 isdesigned as a single piece of material and that the edge strips 16, 18of the covering 2 are folded over in the inward direction and now liebetween the adhesive tape 6 and the silicone paper 10. The folding-overof the edge strips 16, 18 offers the advantage that, when the tear-opentab 3 is pulled, the edge strips 16, 18 can be separated from theadhesive tape 6 by a peeling-type action, for which purpose less forceis required. The tear-open tab 3 here again, as in FIGS. 1-4, consistsof a single layer, but it is designed as an integral part of thecovering 2.

The seam can be covered on the outside surface of the covering 2 bysingle-sided adhesive tape 11, which has the effect of reinforcing thecovering 2, which has been weakened by the seams produced by thestitches.

In practice, the foam strips 1 are compressed to such an extent that,when they expand, they preferably can increase to approximately five orsix times their thickness in the compressed state. Only about half ofthis expansion capacity, however, is actually used, so that it can beguaranteed that secure contact with the part of the building oppositethe profile element to be sealed will be established.

In this context it should be noted that the embodiments shown in thedrawings are illustrated in what amounts to an idealized form of thecross section of the foam strip 1. In reality, all the sides of the foamstrip 1 have bulges as a result of the pressure acting from within, sothat the cross section of the foam strip 1 in the compressed stateassumes a shape deviating from that of a rectangle.

The sealing tape according to FIG. 3 is usually produced in thefollowing way. First, large layers of a foam material 1 are produced,and the top surface is provided with a covering 2. Then seams consistingof threads 7 are sewn into the foam 1 and through the covering 2 beforea piece of adhesive tape 6, covered by silicone paper 10, is attached tothe bottom surface. For the sewing operation, the foam material 1 can beheld down mechanically. Then the sealing tape layer is wound up into awide roll and cut into disks for further processing. Finally, thetear-open-tab 3 is inserted and fastened in place between the individuallayers of the roll, for which purpose the layer on top in the case inquestion must be lifted. Alternatively, the tear-open tab 3 can also beattached after the sealing tape has been unwound from the roll andbefore the sealing tape is wound back up again onto a spool.

It is also possible to introduce the seams subsequently, that is, afterthe sealing tape rolls have been produced and after the sealing tape hasbeen unwound again. For this purpose, the sealing tape must be held downmechanically or provided with an expansion-inhibiting impregnation.After the sewing has been completed, the sealing tape is wound back upagain.

In all of the exemplary embodiments, any desired number of seams can beused, as long as the purpose of the compression of the foam strip 1 isfulfilled. In general, seams extending in the longitudinal direction ofthe sealing tape preferably have a distance of 1 to 5 mm between thestitches, and more preferably a distance of 2.5 to 3.5 mm. Two seamshave a distance of preferably 1 to 5 mm between them in the transversedirection of the sealing tape, and more preferably a distance of 2.5 to3.5 mm. The covering preferably has a thickness of 0.02 to 3 mm, andmore preferably of 0.03 to 1.5 mm. In the compressed state, the foamstrip preferably has a thickness of 1 to 100 mm.

The invention has been described above on the basis of an example of afoam strip with a rectangular cross section, because this makes it mucheasier to explain the invention and its features. The term “rectangular”is also intended to include “square”. The expert will nevertheless seethat the invention can be realized in a corresponding manner with foamstrips which have cross sections deviating from rectangular. Thecross-sectional shape of the foam strip indicated here should thereforenot be understood in a limiting sense, especially since foam stripswhich are originally rectangular can form bulges at the edges betweenthe seams as a result of the expansion pressure.

The expert can use any type of seam which can hold the foam together toa certain degree of compression. So far, only seams extending in thelongitudinal direction of the foam strip have been described. It is alsopossible, however, to use zigzag-shaped seams. Seams extendingtransversely or diagonally can also be used, as long as it is ensuredthat, through the selection of a suitable type of seam, uncontrolledrelease of the seams is prevented in spite of the separation whichoccurs when the sealing tape roll is cut into disks.

1-17. (canceled)
 18. An elastically expanding sealing tape for sealing ajoint between a structural element and an object surrounding thestructural element, comprising: an elastically expanding foam strip, andat least one releasable seam extending across the sealing tape, the seamcomprising at least one thread, which passes through the foam strip, andholding the foam strip in a compressed state.
 19. The sealing tape ofclaim 18 further comprising an adhesive tape, which is arranged in anarea of a bottom surface of the foam strip.
 20. The sealing tapeaccording to claim 18 further comprising a foil-type covering, which isarranged at least in an area of a top surface of the foam strip.
 21. Thesealing tape of claim 20 wherein the seam extends through the coveringand connects the covering firmly to the foam strip.
 22. The sealing tapeof claim 20 wherein the covering is formed at least partially by afabric scrim.
 23. The sealing tape of claim 19 wherein the adhesive tapecomprises a fabric scrim.
 24. The sealing tape of claim 19 wherein theadhesive tape is covered by a silicone paper.
 25. The sealing tape ofclaim 19 wherein the seam extends through the adhesive tape.
 26. Thesealing tape of claim 20 wherein the covering is designed as a wrapping,which surrounds the foam strip on at least two lateral surfaces and atop surface of the foam strip.
 27. The sealing tape of claim 20 whereina tear-open tab is connected to the covering.
 28. The sealing tape ofclaim 27 wherein the tear-open tab is designed as a projecting extensionof the covering.
 29. The sealing tape of claim 27 wherein the tear-opentab is firmly connected to the covering in an edge area of a top surfaceof the foam strip and is folded over so that the covering can be peeledoff by pulling on the tear-open tab.
 30. The sealing tape of claim 20wherein the seam is a two-thread seam having a first thread, whichpasses through the foam strip, of smaller breaking resistance than asecond thread, which links loops of the first thread together on thecovering.
 31. The sealing tape of claim 20 wherein the coveringcomprises two separate sections, which are welded, adhesively bonded, orsewn together at a seam line closely adjacent to the foam strip.
 32. Thesealing tape of claim 18 wherein the seam extends in a longitudinaldirection of the sealing tape, the seam having stitches being 1 to 5 mmapart.
 33. The sealing tape of claim 32 comprising at least two seams,the seams being spaced 1 to 5 mm apart in a transverse direction of thesealing tape.
 34. The sealing tape of claim 20 wherein the covering hasa thickness of 0.02 to 3 mm.
 35. The sealing tape according to claim 19further comprising a foil-type covering, which is arranged at least inan area of a top surface of the foam strip.
 36. The sealing tape ofclaim 35 wherein the seam extends through the covering and connects thecovering firmly to the foam strip.
 37. The sealing tape of claim 35wherein the covering is formed at least partially by a fabric scrim.